MECHANISM OF STRUCTURE FORMATION IN SELF-PROPAGATING THERMITE REACTIONS: THE CASE OF ALUMINA AS DILUENT

Abstract

The mechanism of structure formation of the global reaction Fe₂O₃ + 2Al → 2Fe + Al₂O₃ under self-propagating high-temperature synthesis (SHS) conditions in the presence of alumina as diluent is investigated. The reactants in powder form are converted into products by passing through four transformation zones with different structure and composition. Some of the early stages of this reaction are explained on the basis of the mechanism proposed by Korchagin and Podergin (1979). Final products seem to be then formed as a consequence of a crystallization process from a melt. These findings may contribute to improve the manufacturing of wear and corrosion resistant SHS coatings.

KEYWORDS:

• SHS process
• thermite reactions
• CFQ technique
• structure formation

Additional information

Notes on contributors

GIACOMO CAO

Corresponding author.